The city is shelling out $125 million to replace the 30-year-old Rose M. Singer jail – the only women’s facility at the prison complex – with two facilities for its hundreds of inmates.

Though space will increase by about 225 beds, the Correction Department said the new construction is not about upping capacity, but updating its infrastructure.

“Over the years, the designs of jails have changed,” Correction spokesman Stephen Morello said. “There are ways to place the guards in strategic places so inmates can be watched more carefully. Newer designs actually can make jails safer.”

The original building was built as a temporary facility when the population was high, he said.